the average age of a class of 39 students is 15 years.if the age teacher be included ,then the average increases by 3 months. Find the age of the teacher?

• 25 years
  
  Let teacher's age be, 'x' years, then
  New average including teacher's age=(39*15 + x) / 40 = 15 + (1/4)
  => 585+x = 600+10
  => x=25
• 6 years agoHelpfull: Yes(0) No(0)
• let the age of the teacher be x
  new avg inckuding teacher age is (39*15+x)/40=15+(1/4)
  585+x=600+10
  x=25
• 1 year agoHelpfull: Yes(0) No(0)